Means for energizing electron tubes



- 1,618,028 Feb. 15, 1927. E VROOM MEANS FOR ENBRGIZING ELECTRON TUBES Filed Aug. 20, 1925 i f IlEf mi e/170) fdwara Vraom by %/%4ZM Patented Feb. 15, 1927.

UNITED STATES 1,618,028 PATENT OFF-ICE.

EDWARD VROOM, OF OSSINING, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC OOM- PANY, INCORPORATED, OF NEW YORK, 1\l'r Y., A CORPORATION OF NEW YORK.

MEANS FOR ENERGIZING ELECTRON TUBES.

Application filed August 20, 1923. Serial No. 658,243.

This invention relates to circuits for energizing repeaters, and aims to improve such circuits and reduce the amount of apparatus required therein.

In the specific f orm of the invention shown in the accompanying drawings a' singlebat: tery supply unit is so arranged that it may conveniently be used to supply the plate, filament and grid voltages for electron tube amplifier groups, one group at a time, where the groups employ different numbers of electron tubes or space current paths. By way of example, one of the groups of amplifiers shown may be. regarded as the amplifier of 22 type repeater employing two tubes, an

other group shown may be regarded as the amplifiers'ot' a 21-typc phantom repeater group employing three tubes, and a third group shown may be regarded as the amplifiers of two 22-type repeaters employing two tubes each. The significance of the expressions, 21 type repeater and 22 type repeater, is explained in the article entitled, Telephone repeaters. by Messrs. Gherardi and J ewett, Proceedings of the American Institute of Electrical Engineers, 1919, page 1255; a 21 type phantom repeater group is disclosed in Blackwell Patent No. 1,474,430, November 20, 1923, and in Mathes Patent 1.495.422, May 27. 1924; and 22 and 21 types of repeaters are shown in Figs. 1 and 3, respectively, of Mathes 1,472,610, October 30. 1923, and in Figs. 4 and 3, respectively, of Colpitts 1.128,292, February 16, 1925. Moreover, a common filament circuit battery supplies filament heating current for all of they tubes of which ever one of these three groups is connected to the battery supply circuit, and a common plate current battery supplies current for all of the plate circuits of the group of tubes. Further, in each of the amplifier groups, the space current circuits of the tubes are connected in parallel, and the filament-s of the tubes are connected in series,

and to compensate for the resulting differences in the potential dropbetween the plate and filament in the different tubes of the group, resistances of different values are incorporated in the space current circuits, these resistances being preferably embodied in means for indicating the absence of space current in the tubes, or for indicating absence of filament current since fiow of space currentis, of course, dependent upon flow of filament current.

Fig. 1 of the drawings is a diagram showing a battery supply circuit made in accordance with the invention connected to a repeater group, for instance two 22-type repeaters comprising four filaments connected in series; Fig. 2 is ajdiagram indicating circuit connections employed when the battery bar 6 and its negative pole connected to a bus bar 7 A plate current battery 8 has its its positive pole connected to a grounded bus negative pole connected to bus bar 6 and its positive pole connected'to bus bar 9. Fourelectron tubes 10, 11, 12 and 13 have their filaments fed in series from battery 5. It may be considered, by way of example, that tubes 10 and 11 areamplifiers of one 22-type repeater and tubes 12 and 13 are amplifiers of another 22-type repeater. Space current is supplied to tubes 10 to 13 in parallel from battery 8. Grid potentials for the tubes 10 to 13 are supplied by batteries 14 to 17 respectively. The tubes 10 to 13 may be mounted on, for instance, a repeater panel or panels (not shown) adapted for relay rack mounting, after the general fashion in which the repeater bulbs are mounted on the relay rack panels in D. F. Whiting Patent No. 1,442,456, January 16, 1923, and in Figs. 5 to 7 of the article on Telephone equipment for long cable circuits by G. S. Demarest, Bell System Technical Journal, July 1923. For example. tubes 10 and 11 may be mounted on repeater panel 39, and tubes 12 and 13 on a similar repeater panel 39". Leads from the electrodes of the tubes 10 to 13 connect those electrodes as shown to terminals 40 to 53, each of which may be on the panel upon which is mounted the tube containing the electrode to which that terminal is connected. Thus, the terminals 40, 46, 47, and 53 may be regarded as grid terminals on the repeater panels; the terminals 41, 45, 48 and 52 as plate terminals on the repeater panels; and the terminals 42, 43, 44, 49, 50 and 51 as filament terminalson the repeater panels. Corresponding to the 'repeater panel grid terminals 40, 46, 4i and 53 are battery supply panel grid terminals 20, 26, 27 and 35 respectively, connected thereto, and mounted on a battery supply panel 100 which may also be adapted. for relay rack mounting. Corresponding to the repeater panel plate terminals 41. 45. 48 and 52 are battery supply panel plate terminals 21, 25, 28, and 34, respectively connected thereto and mounted on the panel 100: and also on the battery supply panel 100, are battery supply panel filament circuit terminals 22, 23, 24, 29, 30, 31, 32 and 33. As is shown in the drawing, the battery supply panel filament circuit terminals 22, 23. 24, 30 and 31 and connected to corresponding repeater panel filament terminals 42, 43. 44, 50 and 51, respectively, and the terminal 24 is also connected to the repeater panel filament terminal 49. The battery supply panel filament circuitterminals 29. 32 and 33 are idle in Fig. 1, being provided for facilitatin the insertion in the filament heating C11- cu1t to be connected to the battery supply panel, of resistances 60 and 61 in place of the filaments of tubes 12 and 13 when the filament heating circuit is to contain less than four filaments in'series, as will be explained hereinafter in connection with F1 gs. 2 and 3.

Terminals designated 36. 37 and 38 in the drawing are mounted on the battery supply panel 100, and are strapped together in Fig. 1, these terminals being provided for facllitating the proper connection of a relay 62, the function of which will be pointed out hereinafter, to the plate circuits to be connected to the battery supply panel 100 when the number of space current paths fed from the panel is to be less than four, as will be explained hereinafter in connection with Figs. 2 and 3.

In Fig. 1, relays 65, 66. 67 and 68 have their windings connected in series in the plate circuits of tubes 10. 11, 12 and 13 re spectively, and hold their respective contacts open when the values of the space currents passing through their windings is sutciently high for proper operation of the tubes. If any of these space currents falls below a predetermined value. the corresponding relay will release its armature, thereby causing the energization of a signal lamp 69 and the relay 62, both of which are in a local circuit of a battery 70, the lamp, the winding of relay 62, and battery all three being in series with a circuit comprising the four contacts of relays 65. 66, 67.

and 68 in parallel. Thus the lamp 69 serves as a low space current alarm for the tubes connected to the battery supply panel 100 The relay 62, when energized, closes a local circuit for a.bell or other signal device 71, which therefore also serves as a low space current alarm for the tubes connected to the panel 100. By means of leads such as those indicated at 72 and 73 as connected to a bus bar 74 to which the coil of relay 62 is shown and signal 71 may serve as a low space current alarm for tubes connected to a plurality of battery supply panels, the signal 69, or the correspondmg signal for each panel, indicating the panel to which any space cur rent circuit causing the operation of signal 71 is connected. Preferably the signal 71 is an audible signal and the signal 69 a visual signal.

The filament circuit for the tubes connected to the battery supply panel 100 in Fig. 1 extends from bus bar 6 through a terminal 6 on the panel 100, the upper contacts of a key 75, terminals 31 and 51, the filament of tube 13, the filament of tube 1.2, terminals 49, 24, and 44, and the filament of tube 11, the filament of tube 10,-

terminals 42 and 22, a terminal 7' on the panel 100, a filament current adjusting resistance 76, and a choke coil 77 for reducing fluctuations of filament current due to internal changes in battery 5 or the like, to bus bar 7. The plate circuit for tube 10 extends from bus bar 9 through a terminal 9 on the panel 100, the winding of relay 65, terminals 21 and 41, the plate of tube 10, the space current path in tube 10, and the filament circuit, to bus bar 6.

The plate circuit for tube 11 extends from bus bar 9 through the terminals 9, coil of relay 66, terminals 25 and 45, the plate of tube 11, the space current path in tube 11,

and the filament circuit, to bus bar 6. I

The plate circuit of tube 12 extends from bus bar 9 to the terminals 9' on the panel 100, and through the coil of relay 67, terminals 28 and 48, the plate of tube 12, the space current path in the tube, and the filament circuit to bus bar 6.

The plate circuit of tube 13 extends from bus bar 9 and terminal 9 through the coil of relay 68, terminals 34 and 52, the plate of tube 12, the space current path in the tube, and the filament circuit, to bus bar 6.

The grid circuit for tube 10 extends from the terminal 42 which connects with the negative end of the filament of that tube, to terminal. 22, and through grid battery 14, terminals 20 and 40, to the grid of the tube.

The grid circuit of tube 11 extends from terminal 43, which is at a point on the filament heating circuit located between the negative 'end of the filament of tube 11 and the positive end of the filament of tube 10. through terminal 23, grid battery 15, and terminals 26 and 46, to the grid of tube 11.

supply connections The grid circuit of tube 12 extends from terminal 49 which connects with the negative end of the filament of that tube, to terminal 24 and through grid battery 16, and terminals 27 and 47, to the grid of the tube.

-The grid circuit of tube 13 extends from terminal 51), which is at a point between the negative end of the filament of tube 13 and the positive end of the filament of tube 12, through terminals 30, grid battery 17, and terminals 35 and 53 to the grid of tube 13.

The key 75 has its lower contacts in series with battery 70, so that when the key is operated to open the filament circuit of tubes 10, l1, l2 and 13 at its upper contacts, it will also open the circuit of battery 70, and thereby prevent the operation of the signal devices (it) and 71.

By meansof leads such as those indicated at 78, bus bars (3, 7 and 9 may supply energy from batteries 5 and 8 to battery supply panels (not shown) similar to the battery supply panel 100.

The repeater panel 35) is shown broken away at the left-hand side of tubes 10 and 11. Similarly, the repeater panel 39" is shown as broken away at the left-hand side of tubes 12 and'13. For the sake of simplicity, the apparatus ordinarily associated with the repeating tubes and their battery and mounted on the lepeater panels, has been omitted from the drawing. Only such portions of the alternating current circuits as are included in the direct current and potential circuits, are shown herein.

The batteries 14 to 17, the resistances (i0 and 61, the relay (S5 to 68, the key 75 and the lamp (59 are preferably mounted on the panel 100, as indicated in the drawing.

As explained in A. .F. Rose Patent 1.136.683, November 28, 1922, battery supply circuits for re )eaters. where tubes have their space current circuits in parallel and their filaments in series, the voltage drops in vthe filaments tend to cause the plate-to-filamcnt voltage to be ditferent for the different tubes, and to compensate for this difference, resistances of diti'erent values may be inserted in the space current circuits of the different tubes. In accordance with the preterit invention, the compensating resistances are embodied in the windings ot' the relays to 68, thus reducing the amount of apparatus required and reducing the mounting spacerequired on the battery supply panel. As indicated in the drawing, relay (5? has a resistance greater than that of relay 68; relay 66'has a still greater re sistancc; and relay 65 -21 resistance greater than that of relay 66. The principles underlying the proper proportioning of the resistances are fully set forth in the Rose patent mentioned above.

The windings of relays 65 to 68 serve as choke coils for preventing alternating current output trom any of the tubes fromadapted for relay rack mounting. The electrodes of the tubes 10 to 12 are connected to terminals 240 to- 250 mounted on the panel 39, just as the corresponding elcctrodes of the respectively corresponding tubes 10 to 12 are connected to the respectively corresponding terminals 40 to 50 in Fig. 1. The panel 39 is shown broken away just to the left of the tubes 10 to 12', and the panel 100 in Fig. 2 is shown broken away just to the right of the terminals 20 to 38.

The circuit connections to terminals 20 to 38 in Fig. 2 are shown broken away along the line L, L, which is the same as line L, L in Fig. 1,and these circuit connections to the right of line L, L are to be understood as being the same for Fig. 2 as for 1.

Comparing the circuit connections to terminals 240 to 250 and 20 to 38 of Fig. 2 with the circuit connections to terminals 40 to 50 and 20 to 38 of Fig. 1. it will be seen that all ot'the terminals 240 to 250, except terminal 250, that is, all of the terminals 210 to 249, are connected to terminals 20 to 28 in Fig. 2 exactly as the respectively correspondingtcrminals 40 to 19 are connected to terminals 20 to 28 in Fig. 1. Terminal 30, which in Fig. 1 was strappedto terminal 50 in order to connect the grid circuit of tube 13 to the filament of that tube, is idle in Fig. 2, since the circuit of Fig. 2l1as no tube corresponding to the tube 13 of Fig. 1. In Fig. 2 the resistance 61, which has approximately the value of the resistance of the filament of tube '13 of Fig. 1, is substituted for that filament, in the filament circuit. so that the plate-to-filament'voltages in the tubes 10, 11 and 1-2 will be the same as were the plate-to-filament voltages in the tubes 10, 11 and 12, respectively, and the filament heating current will be the same as in Fig. 1. To accomplish this insertion of resistance 61 in the filament circuit, terminal 31, which in Fig. 1 was strapped to terminal 51 connected to the positive end of the filament of tube 13, is strapped to terminal 32, at the upper end of resistance 61, and terminal 33, which connects with the lower end of resistance 61 and was idle in Fig. 1, is strapped to terminal 250 which connects with the positive, or high voltage, end of the filament of tube 12. Terminals 34 and 35, which in Fig. 1 were strapped to the repeater sponding terminals 40 to 46 in Fig. 1.

panel late andgrid terminals 52' and 53,

respectively of tube 13, are idle in Fig. 2.

of relays ($5, 66 and 67, is idle in Fig. 2,

so that the signalsGS) and 71 will not be operated because of the closed condition of the contact of relay 68.

Fig. 3 shows the circuit connections'to terminals 20 to 38 when panel 1,00 is used to supply the plate, filament and grid circuits of two tubes and 11" having their filaments connected in series. The amplifier group may be, for example, that of a 22-type repeater, such as the repeater comprising the tubes 10 and 11 of Fig. 1, and the tubes 10 and 11" may be mounted on a repeater panel 39 shown broken away just to the left of tubes 10 and 11". The electrodes of the tubes are connected to terminals 340 to 346 mounted on the panel 39, just as the corresponding electrodes of the tubes 10 and 11 are connected to the respectively co il fipanel 100 is shown broken away just to the right of terminals to 38. The circuit connections to terminals 20 to 38 in Fig. 3 are shown broken away along the line L, L, which is the same as the line L, L in Fig. 1 and these circuit connections to the right of lineL, L are to be understood as being the same for Fig. 3 as for Fig. 1.

It will be seen that the interconnections between terminals 340 to 346 and 20 to 26 in Fig. 3 are exactly the same as those between terminals 240 to 246 and 20 to 26 in Fig. 2. In Fig. 3, terminals 27 and 28, which in Fig. 2 were strapped to terminals 247 and 248 connected with the grid and plate, respectively, of tube 12, are idle. In Fig. 3, the terminal 38, which ,connects with the lower end of resistance 51 and which in Fig. 2 was strapped to terminal 250 that connected to the high voltage end of the filament of tube 12' is strapped to terminal 29, so that the resistance 60, which was idle in F ig. 2, is inserted in the filament heating circuit in place of the filament of tube 12, in order to make the value of the filament heating current the same in Fig. 3 as in Fig. 2, and in order to make the plate-tofilament drop in tubes 10", and 11" the same 'as that in tubes 10 and 11 respectively. Terminals 27 and 28, which in Fig. 2 were strapped to the repeater panel plate and grid terminals 247 and 248 respectively, of tube 12, are idle in Fig. 3. minal 37, which connects with the contact of relay 67 and in Fig. 2 was strapped to terminal 38 to connect the contact of relay 67 in parallel with they contacts of relays (i5 and ($6, is idle in Fig. 3, so that the signals 69 and 71 will not be operated because of the closed condition of the contact of relay 67.

The invention claimed is: Y

i 1. In a repeater system, two electron. tube repeater elements each including a filament and an anode, a source of filament heating current, the filaments of said tubes being connected in series circuit with said source,

a source of space current, parallel connec-,. tions from said last named source to the filament and anode of said tubes, and means for indicating the condition of said tubes,

. said means comprising resistance in one of said parallel connections so proportioned as to compensate for the difference in potential drops across the plates and filaments of the difierent tubes due to the series connections of the filaments.

2. In a repeater system, two electron tube repeater elements each including a filament and an anode, a sourceof filament heating current, the filaments of said tubes being connected in series circuit with said source, a source of space current, parallel connections from said last named source to the filament and anode of said tubes, and means for indicating absence of space. current in one of said tubes, said means comprising a relay having a winding in one of said parallel connections, said winding having a resistance so proportioned as to compensate Terfor the difference in potential drops across my name this 18th day of August A. D.,

EDWARD VROOM. 

